U.S. Pat. No. 3,982,622 granted on Sept. 28, 1976, to J. A. Bellino, et al. discloses a printing apparatus including a print mechanism which is intended to ride on a carriage which moves across the width of a record medium. The Bellino et al. mechanism contemplates an inking ribbon positioned between the print mechanism and the record medium. However, the ribbon must not be permitted to touch the paper except as required by the print mechanism in order to form indicia on the record. Any other random touching of the ribbon to the record medium risks smudging or undesirably marking the record medium and is to be avoided. In addition, a fresh ribbon is to be readily mounted in the printer.
The printing mechanism of the Bellino et al. patent is a matrix printer with which elements of the matrix are controlled by an individual print magnet. Axial movement of the printing element (wire) toward and away from the record medium occurs preferably over a minimum of length in order to facilitate the desirably rapid printing. This leaves very little room for neatly and cleanly inserting a fresh ribbon between the record medium and a closely-adjacent print mechanism.
It is desirable to retract the print mechanism during ribbon insertion; however, any adjustment in the ribbon positioning must not be upset. Disturbing any print mechanism adjustments would greatly impair ribbon replacement as these adjustments are normally done by a skilled service-person which skill is not usually present in an operator.